Casein or the like drying machines

ABSTRACT

A casein drying machine has a pair of vertically superposed chambers, the upper feeding to the lower. Gaseous drying medium is fed to the bottom of each chamber, Screens with nonregistering openings are superposed in each chamber and scrapers rotating about a central vertical axis sweep the screens so that the drying casein moves from top to bottom of the apparatus along a circuitous path including a plurality of gravity falls.

United States Patent [1 91 Connor CASEIN OR THE LIKE DRYING MACHINES[75] Inventor: Desmond John Connor, Hamilton,

New Zealand [73] Assignee: Mauri Brothers & Thomson Limited, Sydney, NewSouth Wales, Australia 22 Filed: Dec. '1, 1970 21 Appl.No.: 95,688

[52] US. Cl. ..34/173, 34/182, 34/211 [51] Int. Cl ..F26b 11/12 [58]Field of Search ..34/l73, 182, 185,

[56] References Cited UNITED STATES PATENTS 2,351,676 6/1944 Grandjean..34/173 Primary Examiner-John J. Camby Assistant ExaminerJames C. YoungAttorney-*Young & Thompson [5 7] ABSTRACT A casein drying machine has apair of vertically superposed chambers, the upper feeding to the lower.Gaseous drying medium is fed to the bottom of each chamber, Screens withnon-registering openings are superposed in each chamber and scrapersrotating abouta central vertical axis sweep the screens so that thedrying casein moves from top to bottom of the apparatus along acircuitous path including a plurality of gravity falls.

3 Claims, 13 Drawing Figures PATENTEDHAYZZ I975 SHEET 1 BF 5 FIG.

PATENIEDMAYZZ ms 13.733 714 sum 30F 5 PATENTEUHAYZZ 197a 3.733.714

' SHEET u 0F 5 Fl6.7 H6 6 CASEIN OR THE LIKE DRYING MACHINES Thisinvention relates to improvements in machines designed for use in thedrying of materials such as casem.

This type of machine is well-known and in the past years has taken onseveral forms. For instance, machines employing an endless belt passingsets of rollers for expressing the moisture from the curd or casein havebeen found to be not very efficient, often resulting in a not properly.treated product.

The present invention is concerned with a casein or the like dryingmachine having such a construction and/or arrangement of its parts, thatthe machine is very effective in properly drying the material to thedesired effect.

Generally the invention consists of a casein or the like drying machinecomprising a vertical cylinder divided into two separate chambers, anupper one of the chambers having an upper feed inlet and a lower feedoutlet communicating with a lower one of the chambers providing an upperfeed inlet to the lower chamber which also has a lower feed outlet, eachchamber having a lower gaseous drying medium inlet, an upper gaseousdrying medium outlet, apertured screens fixed at different levels in theheight of each chamber but leaving a gap for a gap in a lower screen outof register with a gap in an upper screen, a vertical shaft extendingthrough both chambers and journalled in the ends of each chamber,scraper members attached to the shaft for each member to be positionedadjacent the upper side of the particular screen, and a drive meansconnected to the shaft, the construction and arrangement being such thatupon wet casein being inserted into the upper chamber through its upperfeed inlet with the shaft and its scraper members being caused to rotateby its drive means and with a gaseous medium being passed into the upperchamber through the lower inlet therefor into this chamber, the wetcasein will first fall onto the uppermost screen and there be moveduntil it falls through the gap in such screen onto the next screen whereit is similarly treated and so on, until it passes through the gap ofthe lowermost screen, the casein during its progress down through theupper chamber being continuously and progressively dried by theup-moving gaseous drying medium which ultimately passes through theupper outlet of the upper chamber in a moisture laden state; the caseindischarges through the lower outlet of the upper chamber and through theupper feed inlet into the lower chamber where the casein is similarlytreated by the screens in this chamber to be continuously andprogressively further dried by up-moving fromthe lower inlet therefor ofthis lower chamber, this gaseous drying medium ultimately passingthrough the upper outlet of this lower chamber in a moisture ladenstate.

In further describing the construction and function of the invention,reference will be made hereinafter to the accompanying drawings, inwhich:

FIG. 1 is anelevation of the machine,

FIG. 2 is a plan on the cylinder,

FIG. 3 is a sectional elevation of the machine,

FIG. 4 is a cross-section taken on the line 4-4 in FIG. 3,

FIG. 5 is a cross-section showing a typical spider member,

FIG. 6 is an enlarged cross-section taken on the line 6-6 in FIG. 2 andFIG. 7 is an enlarged cross-section taken on the line 7-7 in FIG. 5.

FIG. 8 is an enlarged side view of a typical trough or chute with an airpipe,

FIG. 9 is a view taken on the line 9-9 in FIG. 8 showing onecross-section of the trough or chute,

FIG. 10 is a similar view showing another crosssection of the trough orchute and FIG. 11 is a plan of the trough or chute on a different scale,

FIG. 12 is a perspective view of one form of the air pipe, and

FIG. 13 includes perspective views of another form of the air pipe.

In giving effect to the invention the vertical cylinder 10 isone ofpredetermined size or capacity and is divided internally into the twochambers 11,12 by a horizontal baffle or wall 13 which is especiallyformed so as to afford that both chambers are air-sealed from oneanother.

The top of the cylinder 10 is closed by an end plate 14 whilst near thebottom of the cylinder is a bottom wall 15 provided with the lowermaterial or casein outlet 16 of the machine. The total externalperipheral surface of the cylinder 10 excepting inlets and outlets,access doors and drive connections shortly referred to, is

, covered by suitable insulation 17 such as sponge plastics material,rubber or the like. In order to properly contain the insulation an outerperipheral wall 18 is provided consisting of two shells halves or parts,one being fitted to the other. The upper end has two inner angle flanges(not shown) between which is fitted a gas ket providing a joint seal 19.A further upper horizontal sealing wall can be provided a distance apartso as to take the gaseous drying medium inlet of the upper chamber 11and in this instance a secondary inlet is provided in this wall to theupper chamber. Due to this spacing between the two internal horizontalwalls 13, 19, a short duct 20 extends vertically connecting the materiallower outlet of the upper chamber 11 and the material top inlet of thelower chamber 12.

The inlet 21 for the drying medium for each chamber 11 or 12 consists ofa large duct connection located through the composite peripheral sidewall and the outlet 22 for such medium also consists of a large ductconnection passing through such composite wall near the top end of suchchamber 11 or 12. The casein feed inlet to the upper chamber 11 caninclude a mincer 23 operated by the drive means or a separate motor 24with a hopper 25 located below the mincer. This inlet includes an airpipe 26 adapted for connection to a lead from a header (not shown) ofseparate high pressure air fan or air pump. At the material outlet ofeach chamber (11 or 12) for the drying or dried casein there is alsoincluded a wiper arm 27 mounted to extend radially from the center shaft28. In an alternative this inlet can include a small rotary valveadapted to be driven by the drive means; and at the material outlet ofthe lower chamber 12 for the dried casein there can also be included asmall rotary valve (not shown) adapted to be driven by the drive means.

Located at the center of the ends of the cylinder 10 are bearings 29which journal the vertical central shaft 28 mounting the scrapermembers.

Each chamber 11 or 12 is divided internally into a number of separatecompartments dependent upon a pluralityof spiders 30 employed. Thesespiders are fixed at the different levels to mount the screens 31, whichcover the spiders. Desirably there are three separate compartments, thedivision in each case being effected by one of the apertured screens 31that is of a very fine mesh in stainless steel. Each screen 31 issupported by its particular spider 30 which in turn is suitablysupported by the peripheral wall of the cylinder 10.

Each of the three spiders 30 consists of a hub 32 through which thecentral shaft 28 freely passes and rotates and from which hub 32 radiatea plurality of arms 33, such as six arms. The segmental space betweentwo of these arms is covered by part of the fine screen mesh 31. In thescreen part is provided a gap such as a slot 34 that extendssubstantially the radius of the screen.

This slot 34 is connected to act as an inlet to a trough or chute 35 (ofvarious cross-section) in which is located at least one air pipe 36 fordistributing air downward to an outlet side of the trough or chute. Boththe chute and pipe extend the length or substantially the length of theslot 34 in the screen 31. Each air pipe has a series of holes 37, a slot38 or spray nozzles (not shown) and has one end adapted for connectionto a lead from the air fan or pump header. This will ensure that airfrom each pipe 36 will be directed within the trough or chute 35 to forma greater pressure at the discharge end of the trough or chute thanopposed upwardly directed drying air in the particular chamber.

The declining chute is out of register with the slot 34 in the nextlower fixed screen 31, but the outlet of the chute of the lowermostfixed screen of the particular chamber is directly above the loweroutlet 16 of such chamber 12. Instead of each air pipe 36 a small rotaryvalve (not shown) may be located in the respective chute 35 and adaptedto be driven by the drive means. This valve can include a rotorconsisting of two plates each of angle cross-section arrangedheel-to-heel and welded so that there are four arms radiating from thecenter of the rotor and being closed by plates welded to the ends ofsuch arms.

The scraper members according to this embodiment is also six in number,one associated with each particular screen 31 of the respective chamber.Each member consists of a collar 39 having a fixing means by which thecollar is attached to the vertical drive shaft 28. From this collar 39radiate a number of arms 40; to each is mounted a series of scraper orraking blades 41 that are set at an angle, relative to the longitudinalaxis of the particular arm 40. The scraper member is mounted on thedrive shaft 28 at a level so that the bottom edge of its scraper blades41 are just above, such as about /fi 96 inch above the surface of theassociated fixed screen 31. Opposite the screens (31) of each chamber 11or 12 the wall of the cylinder is provided with an access door 42 withsight glasses 43 and preferably lights 44. The peripheral edge of thedoor is backed by a sponge rubber seal 45.

The drive means includes a motor 46 preferably located in a housingmounted on the top end plate 14 of the cylinder 10 and a reduction gear47 the output shaft of which is coupled to the vertical shaft 28.Sprockets and endless chains (not shown) are arranged to drive therotary valves of the casein feed inlet, such outlet and those of thedischarge slots of the particular screen compartments of both chambers.

In use with the machine power driven, heated gaseous medium, i.e. hotair is forced in through the lower air duct 21 of the upper chamber 11and lower heated air is forced in through the lower air duct 21 of thelower chamber 12. The casein in its moist state, wet casein, that iscasein at a moisture of approximately 55 percent is introduced via thehopper 25 and its mincer 23 (if included) in through the top feed inletof the upper chamber 11 onto its top fixed screen 31. The angled blades41 of the top scraper member 40 progressively move the casein around thescreen in a circular pattern with a weaving motion until the caseinreaches the discharge slot 34 of that screen 31. Air from each air pipe36 below this slot now forces the casein down to the next screen 31, andso the casein falls to the next stage where repetition of the operationin the first stage takes place. This air from each pipe 36 forms anairlock by preventing the hot air, used for drying, passing up throughthe particular trough or chute 35 and forming the greater pressure atthe discharge end of such trough than the opposed drying air. Thisoperation takes place for the third stage in the upper chamber 11, whenthe drying casein falls through the casein discharge outlet of the upperchamber 11 and is introduced to the lower chamber 12 via its connectedfeed inlet. Here three stages of operations similar to those in theupper chamber 11 take place. Finally the casein falls through the caseindischarge outlet 16 of this lower chamber which in effect provides afinal drying chamber, and this fine casein riddlings and the driedcasein are removed quickly by the bottom air-sealed conveyor 48, beforeoverdrying and discoloration of these final particles takes place. Thedried casein now has about 10 percent moisture content.

The heated air introduced into each chamber 11 or 12 passes upwardsthrough the apertured screens 31 in that chamber with their layers ofcasein and finally out to atmosphere in a moisture-laden conditionthrough the outlet duct in the upper part of the chamber.

As the machine is enclosed no casein is able to escape from the machineto the surrounding area and any fine dry particles tending to leave themachine into the air-stream are withheld by virtue of having to passthrough the layers of wet casein above it. It will be appreciated thatby having two drying chambers 11 and 12, one supplied with hot air andthe second chamber supplied with air heated to a lower temperature amore even and efficient drying of the casein will take place. Insulationof the body of the machine will prevent heat loss in the vicinity of themachine as well as improving the drying efficiency.

I claim:

1. A casein or the like drying machine comprising a vertical cylinderdivided into two separate chambers, an upper one of the chambers havingan upper feed inlet and a lower feed outlet communicating with a lowerone of the chambers providing an upper feed inlet to the lower chamberwhich also has a lower feed outlet, each chamber having a lower gaseousdrying medium inlet, an upper gaseous drying medium outlet for each saidchamber whereby flow of the drying medium is generally upward througheach of said chambers, apertured gas-pervious screens fixed at differentlevels in the height of each chamber and extending across the chamberbut for a gap through each screen, a vertical shaft extending throughboth chambers and journalled in the ends of each chamber, scrapermembers attached to the shaft and disposed adjacent the upper sides ofthe screens, drive means connected to the shaft to rotate the shaft tocause said scraper memsure in the chute to prevent the drying mediumfrom passing upward through the chute.

2. A casein or the like drying machine as claimed in claim 1 whereineach chute extends substantially the radius of the cylinder and betweentwo arms of the particular spider.

3. A casein or the like drying machine as claimed in claim 1 wherein thescreen comprises a plate of very fine stainless steel mesh.

1. A casein or the like drying machine comprising a vertical cylinderdivided into two separate chambers, an upper one of the chambers havingan upper feed inlet and a lower feed outlet communicating with a lowerone of the chambers providing an upper feed inlet to the lower chamberwhich also has a lower feed outlet, each chamber having a lower gaseousdrying medium inlet, an upper gaseous drying medium outlet for each saidchamber whereby flow of the drying medium is generally upward througheach of said chambers, apertured gas-pervious screens fixed at differentlevels in the height of each chamber and extending across the chamberbut for a gap through each screen, a vertical shaft extending throughboth chambers and journalled in the ends of each chamber, scrapermembers attached to the shaft and disposed adjacent the upper sides ofthe screens, drive means connected to the shaft to rotate the shaft tocause said scraper members to sweep above the screens, means positioningthe gap in each screen out of register with the gap in the next upperscreen in a direction rearward of the gap in the upper screen withrespect to the direction of rotation of said scraper members, a chutemounted under the gap in each screen, and a perforated air pipe locatedin the chute, said pipe being connected to a high pressure air pump anddirecting air downward in the chute and comprising means for creating aback pressure in the chute to prevent the drying medium from passingupward through the chute.
 2. A casein or the like drying machine asclaimed in claim 1 wherein each chute extends substantially the radiusof the cylinder and between two arms of the particular spider.
 3. Acasein or the like drying machine as claimed in claim 1 wherein thescreen comprises a plate of very fine stainless steel mesh.